The remaining year of this grant will be involved with the use of the reductive methylation technique to label C3, C5 and C5a. Activation products of C3 and C5 will be activated using intermediate complement complexes. These fragmentation products will be assessed for biological activity (leukotactic) and examined in SDS-PAGE for estimates of molecular weight by radioautography. We will also initiate a longer term study of physical-chemical changes induced in C5a by the purified chemotactic factor inactivator. We will examine the inactivated C5a for changes in molecular weight (as assessed by SDS-PAGE) and in charge (as assessed by isoelectric focusing).